Eastern US Ill-Prepared for Quakes
CITIES WITHOUT CODES
AS far as preparing for an earthquake, the eastern United States has been asleep at the wheel. The region is just now starting to wake up. While earthquakes occur less frequently here than in California, they're potentially more dangerous and affect a wider area. The region's geology also makes it more difficult to find the faults.
``This is the tragedy,'' says M. Nfi Toksoz, director of the Earth Resources Laboratory at the Massachusetts Institute of Technology. ``For every 100 quakes in California, there's only one here in New England. And the frequency of earthquakes of a certain magnitude are far fewer - we could get a 6.9 here once every 500 years. But because of that, we fall into a false sense of security and complacency.''
Massachusetts has had only one person coordinating earthquakes in its Office of Emergency Preparedness. That position was eliminated in the latest round of budget cuts. While a previously funded study on potential earthquake damage was completed before the cuts, there's no coordinator to turn the survey results into a detailed preparedness plan.
The state has a comprehensive emergency management plan, but conducts no drills, says Douglas Forbes, director of planning for Massachusetts Civil Defense.
``Think of how remarkably efficient and calm the reaction was after the quake in California,'' says Professor Toksoz. ``That demonstrated the importance of public awareness and education.''
New England's geology presents different earthquake scenarios than California's. It's situated on harder basalt, rather than more flexible sandstone, so the stress in the ground is greater. Because motions do not die out as rapidly, a quake here would effect a much larger area.
``An earthquake the same magnitude as the one in California would be felt in 100 times greater an area in New England,'' Toksoz says. The epicenter of a quake last November was 90 miles north of Quebec but was felt as far south as Washington. The 1811-12 New Madrid quakes, on the Arkansas/Missouri border, rang church bells in the Northeast.
Boston; Charleston, S.C.; and the New Madrid fault zone are three places that have had strong earthquakes in the last two centuries. They are being closely watched by the Federal Emergency Management Agency (FEMA). Scientists now say there is a 90 percent chance a quake as strong as San Francisco's will hit the eastern US within 20 years.
``The challenge to us here is even a moderate earthquake could have destructive effects in older cities because of their form of construction, which is largely unreinforced masonry, and the fact that they're built on filled land, which is notoriously unstable. The newer skyscrapers fare better than four-to-five story townhouses,'' says Ken Horak, director of public affairs at FEMA's New England office. Aging bridges, highways, and tunnels also present a problem.
The last major quake to hit the New England area was in 1755, near Cape Ann, Mass.
Some observers wonder how far to go to protect an area that only gets hit every couple of hundred years. Cities and states, however, can strengthen older buildings over time at not too exorbitant a cost, says Robert Whitman, an MIT civil engineering professor, and active in the earthquake engineering effort on a national scale. He estimates that under Massachusett's building code it would be 1 percent or less of total building costs.
``What I would hope is that more cities and states would put earthquake design requirement into codes for new construction and gradually that will lead to a more resistant stock of buildings,'' Professor Whitman says.
While few jurisdictions have done that outside of California, some are starting. Massachusetts adopted seismic standards in 1975. Connecticut and Rhode Island recently adopted them. New York City, Charleston, and Memphis hope to have them soon.
FEMA is planning earthquake drills in the East next year, involving 20 agencies.
``Every part of the nation is undertaking some kind of preparatory planning now,'' says Walter Hays, deputy chief for research applications, at the United States Geological Survey.